Philosophical Review Substance and Independence in Descartes Anat Schechtman University of Wisconsin-Madison Less celebrated than Descartes’s contributions to epistemology, but no less significant, are Descartes’s ventures in metaphysics—in particular, his innovative conception of substance, which marks a decisive break between the modern period and the previous two thousand years in which hylomorphism reigned.1 It is therefore perplexing that Descartes provides not one but two characterizations of substance—which, more- over, are seemingly incompatible. On the one hand, substance is said to be the subject in which properties inhere, and that does not itself inhere in anything. On the other hand, substance is said to be an independent entity. These two characterizations have appeared to many to diverge on I would like to thank Colin Chamberlain, Michael Della Rocca, James Messina, Steven Nadler, Marleen Rozemond, and Tad Schmaltz for detailed and insightful comments on earlier versions of this essay, as well as audience members at the 2015 Oxford Seminar for early modern philosophy and the 2015 Atelier franco-ame´ricain du Se´minaire Descartes for helpful suggestions. I would also like to gratefully acknowledge support from the American Council of Learned Societies and from the Graduate School and the College of Letters and Sciences at the University of Wisconsin-Madison during the time in which this article was written. Finally, as always, I am grateful to John Bengson for everything and more. 1. Arguably, it is likewise Descartes’s conception of substance—no less than his method of doubt, the cogito, or “the way of ideas”—that helped pave the way for the next 150 years of metaphysical and epistemological (including anti-metaphysical and skeptical) developments, in Spinoza, Leibniz, Locke, and Hume, among others. See Wat- son 1987 for an influential discussion of the centrality of Descartes’s metaphysical views for subsequent Cartesianism and its “breakdown.” See also Moore 2013 for a recent sche- matic portrayal of the impact of Descartes’s conception of substance on subsequent philosophy. Philosophical Review, Vol. 125, No. 2, 2016 DOI 10.1215/00318108-3453167 q 2016 by Cornell University 155 Published by Duke University Press Philosophical Review ANAT SCHECHTMAN the definition as well as the scope, or extension, of the notion of sub- stance. For it is often thought that what is the ultimate subject of inher- ence need not—and, in some cases, cannot—be independent. There is, it seems, a tension at the core of Descartes’s metaphysics, afflicting one of its fundamental notions. Readers of Descartes have tended to respond to this tension by prioritizing one of these characterizations of substance at the expense of the other. As a result, they tend to treat passages in which Descartes voices the characterization they disfavor as somehow not expressive of Des- cartes’s considered view—on such occasions, it is sometimes claimed, Descartes “speaks lightly.”2 Other interpreters simply suggest that Des- cartes’s theory of substance is confused or inconsistent. Existing inter- pretations thus tend to handle the tension by avoiding or denying rather than resolving it. My aim in this essay is to develop an interpretation of Descartes’s notions of substance and independence that reconciles his two charac- terizations. If the proposed interpretation is correct, it will allow us to move beyond the apparent tension in Descartes’s metaphysics. It may also point the way to interpretations of other central elements of that meta- physics that are linked to substance and independence, including (but not limited to) the distinction between mind and body and their union, as well as the notions of infinity and perfection, and lead to a better under- standing of the relationship between Cartesian metaphysics and sub- stance monism. The latter position is sometimes said to follow more or less directly from Descartes’s second characterization of substance, as an independent entity. While I will not have the space to examine this con- tention here, it is worth remarking that if my interpretation is correct, there is no straightforward route from the independence of substance to monism.3 What I shall say about the notions of substance and independence in Descartes might also be of interest to contemporary debates in meta- physics concerning relations of grounding and ontological dependence. Much of this debate takes certain historical data-points for granted; for example, that the targeted relation is the same as the one invoked by historical figures like Aristotle or Descartes in characterizing the relation between a substance and its properties. This assumes, of course, that we already know what relations such figures were invoking. But do we? 2. The quoted expression is from Stuart 1999, 100. 3. I discuss this point in detail in Schechtman n.d. 156 Published by Duke University Press Philosophical Review Substance and Independence in Descartes It seems to me that, at least in the case of Descartes, we have yet to achieve a full understanding on this point. For example, if the continuing debate among scholars is any guide, we cannot simply assume that Descartes invokes ontological—as opposed to, say, causal—independence in char- acterizing substance. At least, we cannot do so without further debate—a debate that is undertaken here. I will spell out several problems with existing interpretations before turning to my positive proposal. Stated briefly, the proposal is that in characterizing substance, Descartes invokes a type of indepen- dence that obtains when, and only when, there is no relation to another entity that holds by the nature of the entity in question. Even though the ultimate subject of inherence is sometimes not independent in other respects (for example, modally or causally), it nevertheless satisfies this condition. Consequently, the proposal reconciles Descartes’s two charac- terizations by giving an account of the general notion of independence featured in the second characterization, and of the specific relation of inherence featured in the first characterization as its instance. The main argument on behalf of this proposal arises in response to a suite of historical, textual, and philosophical considerations. Section 1 discusses three important scholastic theses regarding substance, includ- ing the thesis that a substance is the ultimate subject of properties, and provides reasons to think that Descartes endorsed them all. Section 2 turns to the characterization of substance as an independent entity and explores a popular interpretation of it that invokes causal independence. Sections 3 and 4 discuss two other interpretations, which focus instead on absence of inherence and modal independence. Clarifying the difficul- ties confronting these three interpretations will help us to identify desid- erata for a more promising alternative, which sections 5 and 6 then seek to develop and defend.4 4. Unless otherwise noted, translations of Descartes’s works are taken from Des- cartes 1985–1992. The original texts in Latin or French may be found in Descartes 1996. References to Descartes’s work in the main text and notes cite the volume and page number in Descartes 1996 (abbreviated ‘AT’), followed (after a semicolon) by the volume and page number in Descartes 1985–1992, vols. 1 and 2 (abbreviated ‘CSM’), or by the page number in vol. 3 (abbreviated ‘CSMK’). I use the following abbreviations for specific works by Descartes: ‘Rules’ for Rules for the Direction of the Mind,‘Discourse’ for Discourse on Method,‘Meditations’ for Meditations on First Philosophy,‘Principles’ for Principles of Philosophy, ‘Passions’ for Passions of the Soul, and ‘Comments’ for Comments on a Certain Broadsheet. 157 Published by Duke University Press Philosophical Review ANAT SCHECHTMAN 1. Three Scholastic Theses It is fair to say that many central themes in Descartes’s philosophy can be better understood against the background of his scholastic predecessors, who provided him with both a source of influence and a target for criti- cism. In particular, despite obvious differences, Descartes’s notion of substance owes a significant debt to the scholastic tradition.5 This section will highlight three scholastic theses about substance and independence and provide reasons to think that Descartes adopted them as well. First, scholastic authors commonly endorse a conception of sub- stance as the ultimate subject of properties, or accidents. On this con- ception, which has two components, a substance is that to which accidents belong—or in scholastic terminology, that in which accidents exist or inhere—without belonging to (existing or inhering in) anything in turn.6 This conception originates in Aristotle’s Categories, where sub- stance is said to be “that which is neither said of a subject nor is in a subject” (Aristotle 1984, 2a11–19), and appears in later authors, such as Avicenna, who characterizes substance as “that which is not in another as in a subject,” and accident as “that which exists in a subject” (Avicenna 2005, Metaphysics 2.1). While this comment does not make the identifi- cation of substance with subject transparent, the following passage by Sua´rez does, as it explicitly invokes both components of the conception in question: There are two notions or properties indicated by the verb ‘standing under’ [substando] and the name ‘substance’: one is absolute, namely, to exist in itself and by itself [per se] ...; the other is relative, it has to do with supporting the accidents. (Metaphysical Disputations 33.1.1; quoted in Gracia 1982, 267) Others scholastic authors endorse this conception as well, characterizing substance as the subject in which accidents inhere without itself inhering 5. Of course, I do not wish to deny the heterogeneity of views among the scholastics, or to suggest that the particular theses I go on to mention were held by each and every scholastic figure. The intention is only to trace a very general and, I think, plausible line of influence.